ALBERT

Description: As the largest solid waste (SW) generator in the world, China is facing serious pollution issues induced by increasing quantities of SW. The sustainability assessment of SW management is very important for designing relevant policy for further improving the overall efficiency of solid waste management (SWM). By focusing on industrial solid waste (ISW) and municipal solid waste (MSW), the paper investigated the sustainability performance of SWM by applying decoupling analysis, and further identified the main drivers of SW change in China by adopting Logarithmic Mean Divisia Index (LMDI) model. The results indicate that China has made a great achievement in SWM which was specifically expressed as the increase of ISW utilized amount and harmless disposal ratio of MSW, decrease of industrial solid waste discharged (ISWD), and absolute decoupling of ISWD from economic growth as well. However, China has a long way to go to achieve the goal of sustainable management of SW. The weak decoupling, even expansive negative decoupling of ISW generation and MSW disposal suggests that China needs timely technology innovation and rational institutional arrangement to reduce SW intensity from the source and promote classification and recycling. The factors of investment efficiency and technology are the main determinants of the decrease in SW, inversely, economic growth has increased SW discharge. The effects of investment intensity showed a volatile trend over time but eventually decreased SW discharged. Moreover, the factors of population and industrial structure slightly increased SW.

Description: China is the largest CO2 emitter in the world and is still reliant on energy consumption for economic growth. Research has focused on effective approaches of reducing and mitigating CO2 emissions. This paper undertakes a decomposition study of energy-related CO2 emissions from the industrial and household sectors during the period 1996–2012, with the objectives of investigating trends of the changes in energy-related CO2 emissions, the driving forces of these changes, and approaches of mitigating CO2 emission. Results show the following: (1) the expansion of economic activity is the dominant stimulatory factor of the increase of CO2 emissions in China and that a sustained increase in CO2 emissions can be expected; (2) the decline in energy intensity and the adjustment of energy mix and industrial structure effectively mitigate CO2 emissions; and (3) the government should give more attention to enhancing the energy utility efficiency and reducing CO2 emissions in rural households.

Description: Spectral efficient transmission techniques are necessary and promising for future broadband wireless communications, where the quality of service (QoS) and/or max-min fair (MMF) of intended users are often considered simultaneously. In this paper, both the QoS problem and the MMF problem are investigated together for transmit beamforming in broadband multigroup multicast channels with frequency-selective fading characters. We first present a basic algorithm by directly using the results in frequency-flat multigroup multicast systems (Karipidis et al., 2008), namely, the approximation algorithms in this paper, for both problems, respectively. Due to high computational consumption nature of the approximation algorithms, two reduced-complexity algorithms for each of the two problems are proposed separately by introducing the time-frequency correlations. In addition, parameters in the new time-frequency formulations, such as the number of optimization matrix variables and the taps of the beamformer with finite impulse response (FIR) structure, can be used to make a reasonable tradeoff between computational burden and system performance. Insights into the relationship between the two problems and some analytical results of the computational complexity of the proposed algorithms are also studied carefully. Numerical simulations indicate the efficiency of the proposed algorithms.

Description: Integrated analysis on socio-economic metabolism could provide a basis for understanding and optimizing regional sustainability. The paper conducted socio-economic metabolism analysis by means of the emergy accounting method coupled with data envelopment analysis and decomposition analysis techniques to assess the sustainability of Qingyang city and its eight sub-region system, as well as to identify the major driving factors of performance change during 2000–2007, to serve as the basis for future policy scenarios. The results indicate that Qingyang greatly depended on non-renewable emergy flows and feedback (purchased) emergy flows, except the two sub-regions, named Huanxian and Huachi, which highly depended on renewable emergy flow. Zhenyuan, Huanxian and Qingcheng were identified as being relatively emergy efficient, and the other five sub-regions have potential to reduce natural resource inputs and waste output to achieve the goal of efficiency. The results of decomposition analysis show that the economic growth, as well as the increased emergy yield ratio and population not accompanied by a sufficient increase of resource utilization efficiency are the main drivers of the unsustainable economic model in Qingyang and call for polices to promote the efficiency of resource utilization and to optimize natural resource use.

Description: Unprecedented economic achievement in China has occurred along with rising resource consumption and waste productions levels. The goal of sustainability requires the decoupling of economic growth from resource consumption (resource decoupling) and environmental degradation (impact decoupling). For this paper, the performances of resource decoupling (energy and water) and impact decoupling (wastewater, SO2 and CO2) in China were evaluated, and the spatial pattern and temporal trend of decoupling performance were investigated by using the rescaled range analysis (R/S). The results indicate the following. (1) The performance of resource decoupling during the investigated period is worse than that of traditional impact (SO2 and wastewater) decoupling, but better than that of the CO2 emission. Additionally, the decoupling performances of energy consumption and related pollutant emission (except CO2) are better than that of water usage and wastewater discharge; (2) The decoupling performance of energy consumption, SO2 and CO2, has substantially improved from the 10th Five-Year Planning Period (FYP) (2001–2005) to the 11th FYP (2006–2010), which indicates that the decoupling performance is highly related the environmental policy; (3) The spatial disparities of the performance of resource and impact decoupling are declining, which indicates the existence of cross-province convergence in decoupling performance; (4) The decoupling performance of SO2 and water usage in most of regions shows an improving trend. Inversely, the decoupling performance of energy consumption, CO2 emission, and wastewater discharge in most regions show a decreasing trend; (5) China needs more stringent water-saving targets and wastewater discharge standards; better policy efforts to improve the water recycling level both in agricultural, industrial and municipal level are required to prevent the decreasing trend of the decoupling performance.

Description: Matrix theory plays an important role in precoding methodology for multiple input multiple output (MIMO) systems. In this paper, an improved block diagonal (BD) precoding scheme is proposed for a MIMO multicast channel with two users, where the unitary precoding matrix is constructed in a block-wise form by joint triangularization decomposition. In order to reduce large signal-to-noise ratios (SNRs) spread across different transmitted data streams and users, the combination of joint equi-diagonal triangularization (JET) and joint geometric mean decomposition (JGMD) is applied to submatrix construction in the inner process of this precoding scheme. An elaborate implementation is presented, and the existence condition of JGMD is also investigated for two complex-valued matrices with two columns, where the analytical result reveals the connection with the particular channel realization and essentially determines when to consider JGMD for submatrix construction. In addition, the properties of the diagonal elements generated by joint triangularization decomposition are discussed as well as the computational complexity of the proposed scheme. Simulation results indicate that in general, JGMD is employed with high probability in the hybrid model, and the proposed scheme readily outperforms the JET scheme in terms of bit error rate (BER) performance in the moderate to high SNR regimes.

Description: Author(s): Zilong Zhang, Lihua Bai, and Jingtao Zhang We use the classical ensemble method to analyze the nonsequential double ionization of Ar atoms at a lower laser intensity. The correlated-electron momentum distribution is shown. The electron trajectories from recollision-induced ionization (RII) and from recollision-induced excitation with subsequ... [Phys. Rev. A 90, 023410] Published Mon Aug 11, 2014

Description: The improvement of energy consumption efficiency represents a significant task and a critical step toward sustainable energy transformations. This study uses a data envelopment analysis (DEA) and spatial autocorrelation method to conduct comprehensive measurement and assessment research on the economic-environmental efficiency of energy consumption in 31 Chinese provinces. It then carries out a synthetic study on energy consumption efficiency in the context of temporal and spatial dimensions, analyzes the characteristics and patterns related to temporal and spatial evolution, and systematically summarizes the temporal and spatial evolution processes associated with China’s economic-environmental efficiency in energy consumption. The results show that economic efficiency and environmental efficiency, both directly related to energy consumption, are positively correlated and display a parallel and synchronizing relationship. China’s energy consumption efficiency displays an upward trend in general, although differences exist between economic efficiency and environmental efficiency about the growth rate and overall development level. In other words, economic efficiency is generally higher than environmental efficiency. A positive spatial correlation occurs between economic and environmental efficiency in energy consumption across all the Chinese provinces studied. Furthermore, some cluster characteristic can be identified. Accurately, the eastern coastal area of China with a higher efficiency represents a spatial cluster of high values, whereas the midwestern inland area of China with a lower efficiency represents a spatial cluster of low values. Therefore, a descending pattern is displayed from the east to the west. As time goes by, the extent of clustering could become more prominent, accompanied by an increasing spatial cluster of high values and a decreasing spatial cluster of low values. Accordingly, China needs to improve its energy consumption efficiency further and promote sustainable energy transformations.

Description: Eco-efficiency is a tool for sustainability analysis that indicates how to carry out economic activities effectively. This paper assesses agricultural eco-efficiency using data envelopment analysis (DEA) and the Theil index approach. Using basic data of 31 provinces in China during 2003–2013, we analyzed the agricultural eco-efficiency development level and spatial pattern in China. The results show that the agricultural eco-efficiency of only four provinces has been relatively efficient in the entire study period, namely, Zhejiang, Hainan, Chongqing, and Tibet. The results also show that agricultural eco-efficiency was higher mainly in south of the Qinling Mountains-Huaihe River Line and north of the Yangtze River area, that agricultural eco-efficiency is mainly affected by pure technical efficiency, and that highly efficient areas are mainly concentrated in the densely populated areas, i.e., the economic developed areas (except Tibet). The Theil index results show that the agricultural eco-efficiency difference weakened between provinces in China, as did western and northeast regions, but eastern and central regions show a slight upward trend.

Description: The Journal of Organic Chemistry DOI: 10.1021/jo4002036